The present invention relates to improvements in windshield wiper blades and more particularly an assembly for connecting the blade to a wiper arm especially for pin type side mounted arm to blade connection.
Windshield wiper assemblies for motor vehicles include a wiper blade assembly secured to an oscillating wiper arm assembly driven by a power source. The blade assembly comprises a pressure distributing superstructure which supports an elastomeric wiping element and an associated backing strip. The superstructure may include a primary yoke of generally inverted U-shape in lateral cross section having an elongate aperture in the web defined by opposite side walls of the yoke and a pair of aligned openings through the side walls of the aperature for receiving a laterally extending pin for removably securing the blade to the arm with the arm lying generally adjacent the side wall of the primary yoke.
Numerous means have been developed to removably secure a side mounted wiper blade to a wiper arm including plastic inserts mounted in the aperture of the primary yoke with associated latch means. One of the objectives of side mounting a blade with respect to the arm is to maintain a low profile to enable the blade to pass through a small space in those applications where the wiper arm and blade are concealed below the cowl in parked position.
It is also advantageous to provide a plastic insert for a metal superstructure to prevent corrosion and to reduce friction at the junction of components which move relative to each other and also to provide readily accessible and easily manipulatable latching means.
Prior art inserts as exemplifed by Hoebrechts et al, U.S. Pat. No. 4,118,825 and Monarch et al, U.S. Pat. No. 4,324,019 permit the possibility of corrosion at the most vulnerable point where the pin bears in the holes of the side walls of the yoke. The corrosion at this point has been particularly bad when a protective finish on the yoke has been worn through by the pin to expose an unprotected area to salt spray from the road or atmosphere. The corrosion may produce a high friction joint and inhibit pivoting of the wiper blade around the pin; it also can cause enlargement of the opening and failure in addition to the unsightliness created. The insert shown and described in U.S. Pat. No. 4,324,019 discloses a fixed pin. The pin is latched to the end of the wiper arm rather than to the insert which obviates the use of a discrete pin or pin on arm arrangement. The disclosed insert in U.S. Pat. No. 4,118,825 does not provide for corrosion resistance at the openings in the side walls of the yoke and requires removal of the entire insert to release the blade from the arm.